package com.wc.alorithm_blue_bridge._模拟.Q2098;

import java.util.Scanner;

/**
 * @Author congge
 * @Date 2023/10/11 12:18
 * @description 刷题统计
 * https://www.lanqiao.cn/problems/2098/learning/?page=2&first_category_id=1&sort=students_count&second_category_id=3
 */
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        long a = sc.nextLong();
        long b = sc.nextLong();

        long n = sc.nextLong();

        long currentNum = 0;
        long curDay = 0;
        long fiveDay = a * 5;
        long twoDay = b * 2;

        /**
         * 不要有多余的运算
         */
        curDay = n / (fiveDay + twoDay) * 7;
        currentNum = curDay * (fiveDay + twoDay) / 7;
        long[] array = new long[]{a, a, a, a, a, b, b};

        int index = 0;
        while (currentNum < n) {
            currentNum += array[index];
            index++;
            if (index == 7) {
                index = 0;
            }
            curDay++;
        }
        System.out.println(curDay);
    }
}
